Sheet takeout and separation device and sheet processing apparatus

ABSTRACT

A sheet takeout and separation device has a takeout section, a sending section, a separation portion. The takeout section takes out a sheet. The sending section sends out the sheet taken out by the takeout section. The separation portion is provided so as to come in contact with the sheets taken out in an overlapping state by the takeout section, and separates the sheets one by one. In addition, the separation portion has a separation portion main body and a cover. The separation portion main body elastically deforms in accordance with a thickness of the sheet. The cover is provided on the separation portion main body so as to come in contact with the sheet. And, on a surface of the cover, a surface roughening treatment for enhancing a friction coefficient of the relevant surface is performed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2014-168481, filed on Aug. 21,2014, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments relate to a sheet takeout and separation device and a sheetprocessing apparatus.

BACKGROUND

Conventionally, a sheet takeout and separation device is known that isprovided with a takeout section which sucks and sends out a sheet by themovement of a takeout belt formed with suction holes, and a separationsection which is arranged opposite to the takeout section and separatesa sheet which has been sent in an overlapping manner with the suckedsheet.

In the above-described takeout and separation device, in the case inwhich a sheet is made of a material through which air passes easily,when a takeout power is increased by enlarging a suction power, therehas been a case that plural sheets may be taken out simultaneously, andin the case in which a sheet is soft or the separation operation by theseparation section is strong, when a sheet is buckled between thetakeout section and the separation section, there has been a case thatconveying trouble such as a jam may occur. For this reason, in the sheettakeout and separation device, it has been desired to prevent theoccurrence of conveying trouble of a sheet, while properly preventingthat two sheets are sent out in an overlapping manner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a configuration of a sheetprocessing apparatus of an embodiment.

FIG. 2 is a plan view of the sheet takeout and separation device of theembodiment.

FIG. 3 is an enlarged perspective view of the feeding section of theembodiment and its periphery.

FIG. 4 is a perspective view showing a state in which sheets arearranged in the feeding section of the embodiment.

FIG. 5 is a perspective view of the double-sheet takeout preventingblock of the embodiment.

FIG. 6 is a side view of the double-sheet takeout preventing block ofthe embodiment.

FIG. 7 is a plan view of the periphery of the suction holes in theprotection cover of the embodiment.

FIG. 8 is a plan view of the periphery of the suction holes in theprotection cover of the embodiment.

FIG. 9 is an explanation diagram showing a behavior of the double-sheettakeout preventing block of the embodiment.

FIG. 10A, FIG. 10B, FIG. 10C are diagrams each showing a behavior of asheet passing through the separation portion of the embodiment.

DETAILED DESCRIPTION

A sheet takeout and separation device of an embodiment has a takeoutsection, a sending section, a separation portion. The takeout sectiontakes out a sheet. The sending section sends out the sheet taken out bythe takeout section. The separation portion is provided so as to come incontact with the sheets taken out in an overlapping state by the takeoutsection, and separates the sheets one by one. In addition, theseparation portion has a separation portion main body and a cover. Theseparation portion main body elastically deforms in accordance with athickness of the sheet. The cover is provided on the separation portionmain body so as to come in contact with the sheet. And, on a surface ofthe cover, a surface roughening treatment is performed.

Hereinafter, a sheet takeout and separation device and a sheetprocessing apparatus of an embodiment will be described with referenceto the drawings.

FIG. 1 is a perspective view showing a sheet processing apparatus.

As shown in FIG. 1, a sheet processing apparatus 1 is provided with acontroller 1 a, a feeding section 2, a takeout and separation section 3,a main conveying path 4, an inspection section 5, a conveying andsorting section 6, gap correction sections 7, sorting boxes 8.

The controller 1 a totally controls an operation of the sheet processingapparatus 1.

The feeding section 2 holds a plurality of sheets stacked in an uprightposition in an approximately vertical direction with respect to ahorizontal plane, and moves the plurality of sheets toward a stackingdirection. By this means, the feeding section 2 feeds the plurality ofsheets to the takeout and separation section 3 existing at a forefrontside of the stacking direction. The sheet is a letter, for example.

The takeout and separation section 3 sucks and takes out a front sheetin the stacking direction, out of the plurality of sheets fed by thefeeding section 2, and sends out the taken-out sheet toward the mainconveying path 4.

The inspection section 5 reads sorting information described on thesheet.

The conveying and sorting section 6 sorts sheets into four conveyingpaths which are provided at different positions in the verticaldirection.

The gap correction sections 7 are respectively provided immediatelyafter the takeout and separation section 3, at an upstream portion ofthe conveying and sorting section 6, and immediately after the conveyingand sorting section 6. The gap correction section 7 corrects an interval(gap) between adjacent sheets in the conveying direction within aprescribed range.

The sorting box 8 has four steps in the vertical direction. The sortingbox 8 sorts and collects a sheet in accordance with the sortinginformation of the sheet.

Here, the feeding section 2, the takeout and separation section 3, andthe main conveying path 4 compose a sheet takeout and separation device10. In addition, the conveying and sorting section 6 and sorting boxes 8compose a sorting processing section.

FIG. 2 is a plan view of the sheet takeout and separation device, FIG. 3is an enlarged perspective view of the feeding section and a peripherythereof, FIG. 4 is a perspective view showing a state in which sheetsare arranged in the feeding section.

As shown in FIG. 2-FIG. 4, the feeding section 2 of the sheet takeoutand separation device 10 is provided with a flat bottom wall 21 a, and aguide wall 21 b which is provided so as to rise approximately verticallyfrom the bottom wall 21 a. The feeding section 2 holds a plurality ofstacked sheets which are loaded on the bottom wall 21 a in an uprightposition in a feeding direction A toward the takeout and separationsection 3. The guide wall 21 b comes in contact with respective endportions of the plurality of sheets moving in the feeding direction A,to guide the movement of the plurality of sheets.

The feeding section 2 is further provided with a main belt 22 a and subbelts 22 b provided on the bottom wall 21 a, and a backup plate 23 whichmoves on the bottom wall 21 a in the feeding direction A. The main belt22 a and the sub belts 22 b come in contact with respective end portionsof the plurality of sheets loaded on the bottom wall 21 a, and areindependently driven in the feeding direction A. By this means, the mainbelt 22 moves the plurality of sheets loaded on the bottom wall 21 a inthe feeding direction A, and the sub belts 22 b adjust a posture of eachof the plurality of sheets.

The backup plate 23 comes in contact with a rearmost sheet in thefeeding direction A, out of the plurality of sheets arranged on thebottom wall 21 a, presses the plurality of sheets in the feedingdirection A, and moves in synchronization with the driving of the mainbelt 22 a. By this means, the backup plate 23 moves the plurality ofsheets loaded on the bottom wall 21 a in the feeding direction A.

As shown in FIG. 4, in the sheet takeout and separation device 10, thebottom wall 21 a of the feeding section 2 forms a horizontal plane, andthe guide wall 21 b forms a vertical plane orthogonal to the horizontalplane. In each sheet having a surface of a rectangular shape, a side inthe short direction is made approximately in parallel with the verticaldirection. Each sheet is supported by the surface of the bottom wall 21a forming the horizontal plane, at lower side end portions in thevertical direction, out of the both end portions of sides in the shortdirection.

Each sheet is arranged such that a side in the long direction is made inparallel with the horizontal direction, and end portions in a sendingdirection B side of the takeout and separation section 3 describedlater, out of the both end portions of sides in the long direction, arebutted against the guide wall 21 b. By this means, the plurality ofsheets are arranged in the feeding section 2 such that, regarding eachsheet, the end portions of the side in the short direction at the lowerside in the vertical direction are aligned by the bottom walls 21 a, andthe end portions of the side in the long direction at the sendingdirection B side (that is, a forefront portion in the sending directionB) are aligned by the guide walls 21 b.

The takeout and separation section 3 is provided with a sub takeoutportion 31, a main takeout portion 32, a separation portion 33.

The sub takeout portion 31 is arranged at a more upstream side than themain takeout portion 32 in the sending direction B that is in parallelwith the horizontal direction. The sub takeout portion 31 is providedwith a sub air chamber 31 a connected to a negative pressure generator(Not shown. a suction side of a blower or the like, for example), and asuction belt 31 b driven by a drive motor (Not shown. a step motor orthe like, for example).

The sub air chamber 31 a is provided with a sub guide plate 31 d formedwith a plurality of openings 31 c which are opened toward the feedingsection 2. The sub guide plate 31 d is of a rectangular plate shape, andthe plurality of openings 31 c are communicated with the inside of thesub air chamber 31 a. By this means, a negative pressure (a pressurelower than the atmospheric pressure) is given to the openings 31 c ofthe sub guide plate 31 d. The sub guide plate 31 d guides the movementof the suction belt 31 to the sending direction B.

The suction belt 31 b is an endless belt formed with a plurality ofsuction holes 31 e, and is arranged such that at least a part of theregion thereof overlaps with a part of the sub guide plate 31 d. At theregion where the suction belt 31 b overlaps with the sub guide plate 31c, a plurality of the suction holes 31 e of the suction belt 31 bcommunicate with at least a part of the plurality of openings 31 c ofthe sub guide plate 31 d. By this means, a negative pressure is given toa plurality of the suction holes 31 e of the suction belt 31 b by thesub air chamber 31 a via a plurality of the openings 31 c.

At the region where the suction belt 31 b overlaps with the sub guideplate 31 d, the suction belt 31 b faces the plurality of sheets held inthe feeding section 2 in the feeding direction A, and the suction belt31 b moves in the sending direction B, in a state that the suction belt31 b is arranged so as to extend in parallel with the sending directionB. By this means, when a negative pressure is given to the plurality ofsuction holes 31 a, the suction belt 31 b takes out, by suction, a frontsheet in the feeding direction A from the plurality of sheets fed by thefeeding section 2. And the suction belt 31 b sends out the sheet takenout by suction, to the sending direction B at a prescribed speed.

The prescribed speed of the suction belt 31 b is set slower than a speedof a takeout belt 43 described later. By this means, the sub takeoutportion 31 takes out a first sheet from the feeding section 2 bysuction, and sends out the first sheet to the main takeout portion 32,and in addition, takes out a second sheet by suction, after the back endof the first sheet has passed through the sub air chamber 31 a.

And, the suction belt 31 b sends out the second sheet to the maintakeout portion 32 at a speed slower than the speed at which the firstsheet is sent out to the sending direction B by the main takeout portion32. By this means, an interval not less than a prescribed interval valueis provided between the first sheet and the second sheet in the sendingdirection B, to resolve the overlapping of the first sheet and thesecond sheet.

The main takeout portion 32 is arranged at a more downstream side thanthe sub takeout portion 31 in the sending direction B. The main takeoutportion 32 is provided with a valve device 42, the takeout belt 43 whichis driven by a drive motor (Not shown. a step motor or the like, forexample).

The valve device 42 is provided with a main body block 51 formed with amain guide plate 61 on one surface thereof. The main guide plate 61 isarranged so as to face the plurality of sheets held in the feedingsection 2 in the feeding direction A. The main guide plate 61 guides themovement of the takeout belt 43 to the sending direction B.

In the main body block 51 and the main guide plate 61, a plurality ofthrough holes (not shown) which communicate with each other is formed.These through holes are connected to a vacuum pump (not shown) providedin the valve device 42. By this means, a negative pressure is given tothe through holes of the main body block 51 and the main guide plate 61.

The takeout belt 43 is an endless belt in which a plurality of suctionholes 43 a is uniformly formed over the entire region thereof. Thetakeout belt 43 is wound around a plurality of pulleys (not shown)including two pulleys 64 a, 64 b which are respectively arranged at theboth sides of the valve device 42 in the sending direction B. Thetakeout belt 43 is arranged so that at least a part of the region of thetakeout belt 43 overlaps with the main guide plate 61. The plurality ofsuction holes 43 a of the takeout belt 43 communicate with the throughholes (not shown) formed in the main guide plate 61, at the region ofthe takeout belt 43 where it overlaps with the main guide plate 61. Bythis means, a negative pressure is given to a plurality of the suctionholes 43 a of the takeout belt 43.

In addition, the takeout belt 43 moves in the sending direction B, inthe state that the region of the takeout belt 43 where it overlaps withthe main guide plate 61 extends in parallel with the sending directionB. By this means, when a negative pressure is given to the plurality ofsuction holes 43 a, the takeout belt 43 takes out a sheet by suctionwhich is fed in the feeding direction A by the feeding section 2, and issent out to the sending direction B by the sub takeout portion 31. And,the takeout belt 43 sends out the sheet taken out by suction to thesending direction B, at a speed higher than the sending speed by the subtakeout portion 31. At this time, the guide wall 21 b of the feedingsection 2 guides the sending of a sheet to the sending direction B bythe takeout belt 43.

As shown in FIG. 2 and FIG. 3, the separation portion 33 is arranged atan opposite side of the main takeout portion 32, with respect to a sheetsent out in the sending direction B by the main takeout portion 32, at amore downstream side than the guide wall 21 b of the feeding section 2in the sending direction B. The separation portion 33 is provided with adouble-sheet takeout preventing block 71. The double-sheet takeoutpreventing block 71 is arranged so that the double-sheet takeoutpreventing block 71 may face the takeout belt 43 through a gap Stherebetween, at a downstream side of the takeout belt 43 in the sendingdirection B. The gap S is set to about 0.5 mm, for example.

FIG. 5 is a perspective view of the double-sheet takeout preventingblock. FIG. 6 is a side view of the double-sheet takeout preventingblock. As shown in FIG. 6, when a plurality of sheets is taken out bythe takeout belt 43 simultaneously, the double-sheet takeout preventingblock 71 sucks a sheet at the double-sheet takeout preventing block 71side to stop the relevant sheet, and thereby the double-sheet takeoutpreventing block 71 functions not to send a plurality of sheets into thegap correction portion 7 simultaneously.

The double-side takeout preventing block 71 has a main body portion 72formed of elastic material such as urethane rubber (rubber material),for example. The main body portion 72 is formed of elastic material, andthereby the main body portion 72 can be lightened, and also it ispossible to shorten a time for the main body portion 72 to return to theoriginal shape, after the main body portion 72 has been deformed by theentering of a sheet.

An arc surface 72 a is formed on the main body portion 72, at thetakeout belt 43 side (tip side), and also at the entering side (anupstream side in the sending direction B) of a sheet.

A plurality of (6, for example) suction holes 73 is formed at a positionclosest to the takeout belt 43, out of the arc surface 72 a, that is, ata tip of the arc surface 72 a. These suction holes 73 are arranged alonga direction orthogonal to the sending direction B with equal intervals.Each suction hole 73 is connected to a negative pressure generator (Notshown. a vacuum pump or the like, for example) provided in theseparation portion 33. By this means, a negative pressure is given toeach suction hole 73.

At a base end side (an opposite side of the arc surface 72 a) of themain body portion 72, a base plate 74 for fixing the main body portion72 to the sheet takeout and separation device 10 is provided. Inaddition, on the arc surface 72 a of the main body portion 72, and aside surface 72 b where the arc surface 72 a is formed, a support plate75 is formed so as to cover the arc surface 72 a and the side surface 72b.

The base plate 74 and the support plate 75 are respectively fixed to themain body portion 72 using bonding agent or the like. In addition, abase end side of the support plate 75 is fixed to the base plate 74 viaa fixing plate 76 and bolts 77.

The support plate 75 has a role to prevent that the main body portion 72is torn off from the base plate 74 due to the shock when a sheet enters,and a role for supporting that the main body portion 72 returns to theoriginal shape after the main body portion 72 has been deformed. Inaddition, stainless-steel is preferable for the material of the supportplate 75. Stainless-steel is used, and thereby elasticity and rustprevention of the support plate 75 can be ensured. In addition, a wallthickness of the support plate 75 is set to about 0.1 mm, for example,so that the support plate 75 does not affect the deformation of the mainbody portion 72 as far as possible.

Further, a protection cover 78 is provided on the surface of the supportplate 75, at a position corresponding to the arc surface 72 a of themain body portion 72. The protection cover 78 prevents thedeterioration, abrasion of the main body portion 72 and the supportplate 75 due to the shock when a sheet enters.

The protection cover 78 is formed of a metal plate such as astainless-steel plate, for example. A wall thickness of the protectioncover 78 is set to about 1 mm, for example. With the configuration likethis, the protection cover 78 can follow the deformation of the mainbody portion 72. In addition, in the support plate 75 and the protectioncover 78, suction holes 79 are respectively formed at the positionscorresponding to the suction holes 73 of the main body portion 72. Bythis means, a negative pressure is given to the suction holes 79 of theprotection cover 78 via the suction holes 73 of the main body portion72.

Here, a surface roughening treatment M for increasing a frictioncoefficient of the surface of the protection cover 78 is performed onthe protection cover 78, at a periphery of the suction holes 79. Forexample, as the surface roughening treatment M, diamond coating, sandblast, spraying and so on can be cited. For example, when it is assumedthat a friction coefficient μ′ of a place where the surface rougheningtreatment M is not performed is 0.1, the surface roughening treatment Mis performed so that a friction coefficient μ of a place where thesurface roughening treatment M is performed becomes about 0.3-0.5.

Here, to perform the surface roughening treatment M to the periphery ofthe suction holes 79 means to perform the surface roughening treatment Mto the surface within a range separated by each d/2 along the sendingdirection B from the rims of the suction holes 739, when it is assumedthat a diameter of the suction hole 79 is d, as shown in FIG. 7, forexample. In addition, as shown in FIG. 8, the surface rougheningtreatment M may be performed on the surface within a range of a diameterof about 2d, with respect to the diameter d of the suction hole 79,coaxially with the suction holes 79.

Returning to FIG. 2 and FIG. 3, the gap correction section 7, along witha plurality of various conveying belts and rollers (not shown), composea part of a conveying mechanism 80 to convey a sheet. The gap correctionsection 7 is arranged at the downstream side of the separation portion33 in the sending direction B. The gap correction section 7 is providedwith a sponge roller 81 and a drive roller 82 which are arrangedopposite to each other so as to sandwich the main conveying path 4therebetween. The sponge roller 81 is a soft roller having elasticity,and deforms in accordance with the change in a thickness of a sheet tobe conveyed through the main conveying path 4.

The drive roller 82 is rotationally driven by a drive motor (Not shown.an AC servo motor or the like, for example), and changes a conveyingspeed of a sheet by the acceleration and deceleration of the rotation.By this means, when an interval (gap) between a sheet which has beensandwiched by the sponge roller 81 and the drive roller 82, and apreceding sheet in the conveying direction is smaller than a specifiedvalue, the gap correction section 7 decelerates the conveying speed ofthe sheet, to broaden the interval. On the other hand, when an intervalbetween a sheet which has been sandwiched by the sponge roller 81 andthe drive roller 82, and a preceding sheet in the conveying direction islarger than a specified value, the gap correction section 7 acceleratesthe conveying speed of the sheet, to shorten the interval.

Next, an operation of the separation portion 33 will be described, basedon FIG. 2, FIG. 6, FIG. 9 and FIG. 10.

FIG. 9 is an explanation diagram showing a behavior of the double-sheettakeout preventing block when a sheet passes through the separationportion. FIG. 10A, FIG. 10B and FIG. 10C are explanation diagrams of anaction of the separation portion, and each shows a behavior of a sheetpassing through the separation portion.

To begin with, as shown in FIG. 2, a front sheet (a sheet locatedclosest to the sub takeout portion 31 side), out of a plurality ofsheets stacked along the feeding direction A, is sucked and taken out bythe sub takeout portion 31, and the taken-out sheets are sent out to themain takeout portion 32 one by one. A sheet which has been sent out tothe main takeout portion 32 passes through the gap S (refer to FIG. 6)between the double-sheet takeout preventing block 71 of the separationportion 33 and the takeout belt 43 of the main takeout portion 32, andis sent out to the gap correction section 7.

Here, when a thickness of a sheet is equivalent to, or thinner than thegap S between the double-sheet takeout preventing block 71 and thetakeout belt 43, the sheet passes through the gap S, without change.

On the other hand, when a thickness of a sheet is thicker than the gap Sbetween the double-sheet takeout preventing block 71 and the takeoutbelt 43, as shown in FIG. 9, an end portion of the sheet at the sendingdirection B side comes in contact with the protection cover 78 of thedouble-sheet takeout preventing block 71. Further, the sheet presses thedouble-sheet takeout preventing block 71. Then, the double-sheet takeoutpreventing block 71 is compressed and deformed so that it is slightlybent backward toward the downstream side in the sending direction B. Andthe sheet passes through the gap S while pressing the double-sheettakeout preventing block 71 away.

Here, when it is assumed that a radius of curvature of the arc surface72 a formed on the main body portion 72 of the double-sheet takeoutpreventing block 71 is R, a wall thickness of the protection cover 78 ist, a maximum thickness of a sheet is Hmax, and the gap between thedouble-sheet takeout preventing block 71 and the takeout belt 43 is S,as shown in FIG. 6, FIG. 9,

the radius of curvature R is set so as to satisfy

R≧(Hmax−S)×2−t  (1).

When the expression (1) is satisfied, it is possible to set a positionof a contact point P (refer to FIG. 9) where the protection cover 78 andthe sheet contact, so that an angle θ which a line connecting thecontact point P and the center of the arc surface 72 a and a lineconnecting the suction hole 93 of the protection cover 78 and the centerof the arc surface 72 a make becomes not more than 60 degrees. In otherwords, the contact point P that contacts the sheet can be set within arange of R/2 from the tip of the takeout belt 43 side of the main bodyportion 72. For this reason, when the main body portion 72 is pressed bythe sheet, it is possible to set a direction of the force acting on themain body portion 72 by this pressing force, to a direction to which themain body portion 72 is surely compressed.

In addition, it is preferable to set a size of the main body portion 72in the length direction (a vertical direction in FIG. 6) to not lessthan about 5 times the maximum deformation amount (Hmax−S) of the mainbody portion 72. When set in this manner, the compression deformationdistortion of the main body portion 72 can be decreased as much aspossible, and thereby it is possible to enhance the durability againstfatigue destruction, when the main body portion 72 is repeatedlydeformed.

In addition, since the surface roughening treatment M is performed onthe protection cover 78 only at the periphery of the suction holes 79(refer to FIG. 5), when the double-sheet takeout preventing block 71 iscompressed and deformed so that it is slightly bent backward toward thedownstream side in the sending direction B, the place where the surfaceroughening treatment M is performed faces toward the downstream side inthe sending direction B. For this reason, when a thick sheet comes incontact with the protection cover 78, the sheet comes to make contactwith the place of the protection cover 78 where the surface rougheningtreatment is not performed, and thereby the friction between theprotection cover 78 and the sheet does not increase. Accordingly, thesheet can smoothly pass through between the double-sheet takeoutpreventing block 71 and the takeout belt 43.

Next, a case in which two sheets are sent out from the main takeoutportion 32 in an overlapping manner will be described.

When two sheets conveyed by the main takeout portion 32 try to passthrough the gap S between the double-sheet takeout preventing block 71and the takeout belt 43 in an overlapping state, as shown in FIG. 10A, asheet at the double-sheet takeout preventing block 71 side, out of thesheets in an overlapping state, is sucked by the suction holes 79 of thedouble-sheet takeout preventing block 71, and stops on the spot, asshown in FIG. 10B. Since, a large friction force does not act on betweenthe sheets in an overlapping state, the sheet at the takeout belt 43side is sent out to the gap correction section 7 without change.

Here, the surface roughening treatment M is performed on the protectioncover 78 of the double-sheet takeout preventing block 71, at theperiphery of the suction holes 79 (refer to FIG. 5). For this reason, afriction force between the periphery of the suction holes 79 and thesheet sucked by the suction holes 79 becomes large. Accordingly, it ispossible to surely stop one of the sheets in an overlapping state, bythe double-sheet takeout preventing block 71, while weakening thesuction force (negative pressure) of the double-sheet takeout preventingblock 71.

In addition, the plurality of suction holes 79 provided in theprotection cover 78 are arranged along a direction orthogonal to thesending direction B with equal intervals (refer to FIG. 5). For thisreason, it is possible to prevent that the sheet sucked by thedouble-sheet takeout preventing block 71 might be rotated (skew) aroundone point.

Subsequently, when the sheet at the takeout belt 43 side completelypasses through the double-sheet takeout preventing block 71, as shown inFIG. 10C, the sheet which has been stopped by the double-sheet takeoutpreventing block 71 is sucked to the takeout belt 43 side. And thissheet is sent out to the gap correction section 7 without change.

Here, a suction force of the valve device 42 of the main takeout portion32 against a sheet is set sufficiently larger than a suction force ofthe separation portion 33 against a sheet. For this reason, when thesheet at the takeout belt 43 side has completely passed through thedouble-sheet takeout preventing block 71, the sheet which has beenstopped by the double-sheet takeout preventing block 71 is surely suckedto the takeout belt 43 side.

In addition, when at least one sheet out of overlapping two sheets issufficiently thick, the sheet at the double-sheet takeout preventingblock 71 side comes to stop in front thereof, without reaching thesuction holes 79 of the protection cover 78. That is, a force by whichthe sheet at the double-sheet takeout preventing block 71 side tries topress the double-sheet takeout preventing block 71 away acts on as aresistance force, and thereby the sheet stops, and during this time, thesheet at the takeout belt 43 side is sent out to the gap correctionsection 7. For the reason, sheets still in an overlapping state can besurely separated by the separation portion 33, regardless of thethicknesses of the sheets.

In addition, as described above, a prescribed speed of the suction belt31 b in the sub takeout portion 31 is set slower than a speed of thetakeout belt 43 in the main takeout portion 32. For this reason, aninterval not less than a prescribed interval is provided between a sheet(first sheet) which has firstly been sent out from the feeding section2, and a sheet (second sheet) which has been sent out next, and therebythe overlapping of the first sheet and the second sheet can be resolved.Accordingly, it is possible to prevent that the sheet which has beenstopped by the double-sheet takeout preventing block 71 might overlapagain with a sheet located in a more upstream side than this sheet inthe sending direction B.

In this manner, in the double-sheet takeout preventing block 71 of thepresent embodiment, the surface roughening treatment M is performed onthe protection cover 78 provided on the main body portion 72. For thisreason, when sheets still in an overlapping state are conveyed by thetakeout belt 43, it is possible to surely stop a sheet at thedouble-sheet takeout preventing block 71 side, using a friction force ofa place where the surface roughening treatment M is performed.Accordingly, it is possible to prevent that a plurality of sheets issent out in an overlapping manner, and the occurrence of conveyingtrouble can be prevented. In addition to this, it is possible tostrengthen a stopping power of a sheet without increasing the suctionforce of the separation portion 33, and it can be prevented that aplurality of sheets is sent out in a overlapping manner, and thereby thesheet takeout and separation device 10 (a negative pressure generatorand so on provided in the separation portion 33) can be miniaturized.

In addition, the main body portion 72 is formed of elastic materialwhich elastically deforms in accordance with the thickness of a sheet,and further the surface roughening treatment M is performed on theprotection cover 78 at the periphery of the suction holes 79. For thisreason, overlapping sheets can be efficiently stopped by the suctionholes 79, and in addition, it is possible to prevent that a thick sheetor the like might be damaged by a place where the surface rougheningtreatment M is performed.

Further, the protection cover 78 of the double-sheet takeout preventingblock 71 is of a metal plate (stainless-steel plate, for example). Forthis reason, it is possible to set a friction coefficient of a placewhere the surface roughening treatment M is not performed low, whilekeeping the stiffness of the protection cover 78 itself. Accordingly,when sheets do not overlap and the sheets are conveyed one by one, thesheets can smoothly pass through on the double-sheet takeout preventingblock 71.

In addition, a plurality of the suction holes 79 of the protection cover78 is formed with equal intervals along a direction orthogonal to thesending direction B. For this reason, the suction holes 79 can preventthat a sheet sucked by the double-sheet takeout preventing block 71 isrotated (skew) around one point. That is, when a sheet is stopped at onepoint, there is a possibility that the sheet might be skewed around thatpoint. But a sheet is stopped at at least two or more points, andthereby it can be prevented that a sheet might be skewed.

Further, the double-sheet takeout preventing block 71 is arrangedopposite to the takeout belt 43 through the gap S, at the downstreamside of the sending direction B in the takeout belt 43. For this reason,when sheets still in an overlapping state are conveyed by the takeoutbelt 43, while one sheet out of these sheets is stopped by thedouble-sheet takeout preventing block 71, the other sheet can surely besent out to the gap correction section 7 by the takeout belt 43.

In addition, on the main body portion 72 of the double-sheet takeoutpreventing block 71, the arc surface 72 a is formed at the takeout belt43 side (tip side), and also at the entering side of a sheet (upstreamside in the sending direction B). For this reason, the double-sheettakeout preventing block 71 can smoothly receive a sheet.

Further, the radius of curvature R of the arc surface 72 a is set so asto satisfy the expression (1). For this reason, when the main bodyportion 72 is pressed by a sheet, it is possible to set a direction ofthe force acting on the main body portion 72 by this pressing force, toa direction to which the main body portion 72 is surely compressed.

In the above-described embodiment, the case has been described that thesurface roughening treatment M is performed only to the periphery of thesuction holes 79 in the protection cover 78 of the double-sheet takeoutpreventing block 71. But without being limited to this, the surfaceroughening treatment M may be performed to the whole surface of theprotection cover 78. In addition, the surface roughening treatment M maybe performed to only about a half of the whole surface of the protectioncover 78 including the periphery of the suction holes 79. In this case,it is necessary to set a friction coefficient by the surface rougheningtreatment M, so that the surface roughening treatment M does not damagea sheet.

In addition, in the above-described embodiment, the case has beendescribed in which the surface roughening treatment M is performed tothe protection cover 78, by diamond coating, sand blast, spraying, andso on, for example. But the surface roughening treatment M is notlimited to this, a tape, a rubber sheet, or the like for enhancing thefriction resistance may be pasted on the surface of the protection cover78. In this case, it is desirable to perform a replacing operation of atape or a rubber sheet, in accordance with the using frequency of thesheet processing apparatus 1.

In addition, in the above-described embodiment, the case in which theprotection cover 78 is formed of a stainless-steel plate, for example,has been described. But the protection cover 78 is not limited to this,the material of the protection cover 78 may be material, if a frictioncoefficient at the surface of the material is low. For example, thematerial may be engineering plastics of which abrasion resistance wasexamined.

According to the sheet takeout and separation device and the sheetprocessing apparatus as described above, since the surface rougheningtreatment M is performed on the protection cover 78 of the double-sheettakeout preventing block 71, it is possible to surely prevent that aplurality of sheets are sent out in an overlapping manner, and theoccurrence of conveying trouble can be prevented. In addition, since itis possible to prevent that a plurality of sheets are sent out in anoverlapping manner, while weakening the suction force of the separationportion 33 as much as possible, the sheet takeout and separation device10 (a negative pressure generator and so on provided in the separationportion 33) can be miniaturized.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A sheet takeout and separation device,comprising: a takeout section to take out a sheet; a sending section tosend out the sheet taken out by the takeout section; and a separationportion which is provided so as to come in contact with the sheets takenout in an overlapping state by the takeout section, and separates therelevant sheets one by one; wherein the separation portion includes aseparation portion main body which elastically deforms in accordancewith a thickness of the sheet, and a cover which is provided on theseparation portion main body so as to come in contact with the sheet,wherein a roughening treatment has been applied on a surface of thecover.
 2. The sheet takeout and separation device according to claim 1,further comprising a suction hole for sucking the sheet provided in acontact surface of the separation portion to contact with the sheet, andthe surface roughening treatment is performed on the cover so as tosurround at least a periphery of the suction hole.
 3. The sheet takeoutand separation device according to claim 1, further comprising aplurality of suction holes aligned perpendicular to a conveyingdirection of the sheet for sucking the sheet provided in a contactsurface of the separation portion to contact with the sheet, and thesurface roughening treatment is performed on the cover so as to surroundat least a periphery of the suction holes.
 4. The sheet takeout andseparation device according to any one of claim 1 to claim 3, whereinthe separation portion faces the sending section via a gap, at adownstream side in a sheet sending direction in the sending section. 5.The sheet takeout and separation device according to claim 4, whereinthe separation portion main body is in the form of an arc surface at anentering side of the sheet.
 6. The sheet takeout and separation deviceaccording to claim 5, wherein when it is assumed that a radius ofcurvature of the arc surface is R, a wall thickness of the cover is t, amaximum thickness of the sheet is Hmax, and the gap is S, the radius ofcurvature R is set so as to satisfyR≧(Hmax−S)×2−t.
 7. The sheet takeout and separation device according toclaim 5, wherein the separation portion further has a support platefitted on the separation portion main body at the entering side of thesheet, and the cover is fitted on the support plate.
 8. The sheettakeout and separation device according to claim 2, wherein the sendingsection has a suction hole for sucking the sheet, and a suction force ofthe suction hole of the sending section is larger than a suction forceof the suction hole of the separation portion.
 9. The sheet takeout andseparation device according to claim 3, wherein the sending section hasa belt formed with the suction hole of the sending section.
 10. Thesheet takeout and separation device according to claim 4, wherein theseparation portion is provided so as to come in contact with the sheetlocated at an opposite side of the sending section, out of the sheetstaken out in an overlapping state by the takeout section.
 11. A sheetprocessing apparatus, comprising: the sheet takeout and separationdevice according to any one of claim 1 to claim 10; and a sortingprocessing section to perform sorting processing of the sheet sent outby the sending section.